1. Field of the Invention
The present invention relates to orthopedic devices. More particularly, the present shoulder sling provides stable and secure support to a wearer's arm at a variety of angles of abduction and external rotation.
2. Description of the Related Art
Physicians frequently treat many shoulder ailments with shoulder slings. For example, following a shoulder dislocation or shoulder surgery, a physician may place the patient's affected arm in a sling so that the shoulder remains motionless while it heals. Many simple slings comprise just a pouch that is supported by a strap around the wearer's neck. The wearer's forearm rests within the pouch such that the elbow is at a 90° angle and the forearm extends across the wearer's abdomen. U.S. Pat. Nos. 4,372,301, 4,622,961 and 4,834,082 provide examples of such simple slings.
For certain shoulder treatments it is advantageous for the patient to maintain his or her shoulder at certain angles of abduction, extension and rotation. For these treatment situations, a physician frequently employs a sling that includes an elevation support device. The elevation support device maintains the wearer's arm at the desired angles, while straps and/or a pouch maintain the position of the wearer's arm relative to the support device.
U.S. Pat. No. 5,334,132 discloses an arm sling including a forearm support section 22 that is supported by a shoulder strap 18 and a waist strap 20. The forearm support section 22 includes a pocket 50 on a side facing the wearer. The pocket 50 encloses a foam cushion 52 that abuts the patient's waist and maintains the wearer's arm at a small abduction angle.
U.S. Pat. No. 4,598,701 discloses a shoulder abduction splint comprising a unitary block of synthetic foam material that supports the wearer's arm at a desired abduction angle. A plurality of straps 24, 26, 28, 29 support the block. The block includes a flat surface C that abuts the wearer, and a second surface B that supports the wearer's arm at approximately 45° of abduction. The block further includes a flat lower surface A. When the block is inverted, the lower surface A supports the wearer's arm at approximately 90° of abduction.
Current shoulder slings, including those slings described above, provide inadequate restraint against undesired shifting or rotation of the sling relative to the wearer. With each of these slings, generally a plurality of straps suspend the arm support portion from the wearer's neck and/or shoulders. These straps function only to retain the arm support portion at a desired height. If a strap is provided that wraps around the wearer's torso, this strap functions only to prevent the wearer's arm from reaching a greater abduction angle. None of the straps are properly positioned or tensioned to prevent other shifting of the wearer's arm that causes changes in the angles of extension and rotation. Such undesired shifting can lessen the effectiveness of the sling at treating the wearer's shoulder.
Current shoulder slings also do not support a wearer's arm at positive angles of external rotation. Some slings suspend the wearer's arm at 0° of abduction and 0° of rotation. Some suspend the wearer's arm at 0° of abduction and a positive angle of internal rotation. Finally, some suspend the wearer's arm at a positive angle of abduction and 0° of rotation.
Therefore, a shoulder sling that supports a wearer's arm at positive angles of external rotation, and that restrains the wearer's shoulder against undesired extension and rotation would be of great benefit to people with shoulder ailments.